1. Field of the Invention
This invention relates to submersible pumps and more specifically to a check valve for such an apparatus.
2. The Prior Art
When water wells are new, debris resulting from the well drilling operation will be dispersed throughout the well. This debris is primarily residue of the drilling lubricant and cooling medium, that is, drilling mud and stray trash from both the surface and penetrated soil. Examples of such debris are small root pieces and pine needles. Eventually, such debris will either settle or be pumped out. However, their presence in a new well poses a threat to proper operation of a submersible pump check valve, which is particularly subject to stringy debris impairing its ability to close.
In the case of the check valve being restrained from closing, one solution is to pull the pump from the well, clean the check valve, and lower the pump back into the well for continued operation. This procedure has been practiced extensively and check valves intended for this service have been made with this function in mind. The manufacture or design of prior art pump check valves has been such that while the poppet may be removed it is necessary first of all to pull the pump from the well, clean the check valve and/or replace the entire pump and lower the pump back into the well for continued operation. The prior art has contemplated that removal of the poppet would allow replacement of a worn sealing member in lieu of discarding an otherwise useable pump.
Because of the necessary machining costs involved, the manufacture of check valves in the prior art has been more expensive than desirable.